Yeah... it occurs to me that I don't have any clue whatsoever how spirits are created. I know what they are and all that, but now that my curiosity's been piqued, I need to know an answer. Does anyone know how spirits are created?

Well, I understand that human ghosts themselves are created by their souls and consiousness by death. Usually by a tramatic death or a death with still strong feelings left unanswered or resolved, or fear would keep a human spirit tied down to Earth and become a ghost. And there are Residual ghosts, those whom have died all the same but the death was so tramatic that they still believe their alive, repeating everything in detail to the point of their death over and over again like a broken record, unknowning to the physical world or anything else, sad really. But a spirit on the other hand, a demon or angel I believe could be made from a human spirit if certain things become checked and done (if you go to Heaven, your an angel, vice versa for Hell)at least this is what I think.

thats a tricky one to answer considering im not quite sure, i mean i once created one or something that kinda felt like one but anyway if i have to point you in a derection of a book i would chose this one
Familiar Spirits; A Practical Guide For Witches & Magicians

i would ask that you do not deviate from instructions too much. it just get messy if you do.
sincerly
priest of practical witches
micah

Spirits are energy bodies powered by the life source of the soul similar to how our physical bodies are believed to be powered by the energy of the nervous system. The energy of a spirit is more complicated than just life energy. Our auras are just a taste of that diversity of energy. The spiritual body contains a complex system of what some may call "chakras", something likened to our physical organs. Each control a different aspect of the spirit itself. Everyone of our bodies contain a spirit/soul. When our physical bodies die, the spirit/soul is released to roam freely on the astral and ethereal planes. When we are incarnated, our souls enter the body as a vessel to live without memory of our previous existence in order to learn, heal, or experience that which we cannot spiritually.

"Spirits of" are essences of certain energies that contain intelligence.

Higher beings such as what some refer to as "demons" don't really "need" to be incarnate. They are not your average spirit and have gifts that cause them to be far wiser naturally and they are stronger spirits, so they don't have the same weaknesses to spiritual/emotional/mental injury. You can always tell the difference between a normal spirit and a higher being by the strength of the presence they exude.